Q&A - PSLE Science

[Verysuperkiasu]

atutor2001:

In conclusion, such question (where the outcome depends on many other variables) should not appear under MCQ, unless one of the option is that \"the plant may or may not survive\", which is the most accurate answer.

Thanks for the informative update! Appreciate that

[chrisu]

This is a MCQ question of my daughter's Science Prelim paper 2011;


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Anyone knows the answer and care to explain why? I find the second part \"reason to keep temp. at 37deg\" difficult to tell if one is not familiar with such bacteria. Also how we expect a P6 student to know \"dextrose\", even adult may need to Google to know it.

Sometimes I wonder if this type of question suitable for primary school student? If the students are taught in detail for such topic, then it's fine but sad to say, NO.

[Nebbermind]

I wld have chosen (3).


Providing food’ seems more sensible than ‘preventing evaporation’, and
‘37deg’ relates more to body temp than room temp.

[atutor2001]

I think the question is quite reasonable. The main test of the question is "inference" skill. The only shortcoming in the question is that it did not highlight that Yakult is for human consumption and the purpose of drinking Yakult is to introduce good bacteria to our stomach.


Students will not know what is dextrose. However, they are expected to know that sugar is commonly used to feed yeast and bacteria (as food) when we cultivate them. Therefore, with our knowledge on the purpose of sugar, the option automatically inferred that dextrose is also a form of food.

Since the bacteria in Yakult is intended to stay and grow in the stomach, the question on why the drink is prepared at 37 degree C is actually testing the logical thinking that it would be better to grow the bacteria at 37 degree so as to prepare them to survive in the same temperature as our body.

[chrisu]

Thanks atutor2001 and nebbermind. Yes the answer is (3). Since this is the MCQ portion, guess the students need to answer within 2 minutes is quite tough.

[Sun_2010]

chrisu:

Thanks atutor2001 and nebbermind. Yes the answer is (3). Since this is the MCQ portion, guess the students need to answer within 2 minutes is quite tough.

Agree with atutor2001 that it is reasonable

Yes the question is tough but within the grasp of a P6 child. Afterall it is about applying our knowledge to real life scenarios, logical thinking. Some such questions are necessary to separate out the levels. As long as the paper is not filled with such questions I feel it is fair.


PS- I think my daughter had a similar Q last year in SA1 or Prelim ....

[Verysuperkiasu]

:oops: Came across a question from Pei Chun prelim 2011 section B Q38


Expt is about 3 similar springs suspended by materials A, B, C (all 50g). 2 pieces of object X are placed below A and C. Picture shows A suspended very high up furthest from X below it. while C is very closed to X below it. B is suspended in the middle.

There is one part that asks what can X be. - Answer should be a magnet as both A and X repelled each other.

But next question ask 'what material is block A made up of- explain.
Both A and X have to be magnets (they repel) but can the material be called 'lodestone' or 'iron'?

(sorry I don't have a scanner so hv to describe the picture) :oops:
hope one of u can help??

[atutor2001]

The questions is \"what material is block A made up of?\" The word \"is\" means \"definitive\" i.e. must be correct.


Therefore, putting either lodestone or iron will be wrong because we can't be sure/definite that it is iron or lodestone.

The correct answer is \"magnetic material\" because, all and only, magnetic material can be made into a magnet.

[Verysuperkiasu]

atutor2001:

The questions is \"what material is block A made up of?\" The word \"is\" means \"definitive\" i.e. must be correct.


Therefore, putting either lodestone or iron will be wrong because we can't be sure/definite that it is iron or lodestone.

The correct answer is \"magnetic material\" because, all and only, magnetic material can be made into a magnet.

Oh, I see. You mean if the question asks 'what possible material can A be made up of' then I am right to put lodestone or iron?

[Verysuperkiasu]

atutor2001:

The questions is \"what material is block A made up of?\" The word \"is\" means \"definitive\" i.e. must be correct.


Therefore, putting either lodestone or iron will be wrong because we can't be sure/definite that it is iron or lodestone.

The correct answer is \"magnetic material\" because, all and only, magnetic material can be made into a magnet.

Oh, I see. You mean if the question asks 'what possible material can A be made up of' then I am right to put lodestone or iron?